EU regulators back blood cancer stem cell therapy

MolMed’s Zalmoxis is an add-on treatment for adults receiving a stem cell treatment for types of blood cancer to aid immune reconstitution and reduce risk of graft-versus-host disease.

Zalmoxis is classified as an advanced therapy medicinal product, and in the likely event of approval by the European Commission it will become one of a handful of such medicines to have made it to market.

This involves non-specialised precursor cells, which can develop into specialised types of blood cell, from a partially matched donor to help the bone marrow produce healthy blood cells.

Used in serious blood diseases such as haematological malignancies including leukaemia and lymphoma, these transplants are more readily available than perfect matches but carry a higher risk of graft-versus host disease, where transplanted cells attack the recipient’s organs, leading to organ damage.

Zalmoxis consists of T cells from the stem cell donor, separated from the rest of the cells in the transplant, which have been genetically modified to include a “suicide gene” called HSV-TK.

The suicide gene in Zalmoxis makes the T cells susceptible to a medicine called ganciclovir. If the patient develops graft-versus-host disease, ganciclovir is given, killing the T cells that have the suicide gene and preventing further development of the disease.

The CHMP scientific committee recommended a conditional approval, which allows for marketing before the availability of confirmatory clinical trial data. Such approvals are reviewed by EMA experts annually until the data is available.

Approval was based on overall survival data from 45 patients treated with Zalmoxis, compared to rates of survival from databases of patients who have undergone haploidentical HSCT.

Survival rates were higher for patients who received Zalmoxis (49% survival after one year, compared to 37% for patients who did not receive Zalmoxis).

The last advanced therapy recommended by the CHMP was GlaxoSmithKline’s Strimvelis in April, for the very rare genetic immune disorder, SCID.

Earlier this month, the EMA published a report considering ways to encourage development of advanced therapies.